Picking motion for looms



Nov. 23, 1948. J. HEATON rxcxme monou Fox LOOMS 2 Sheets-Sheet 1 Filed NOV. 26; 1945 NOV. 23, J. HEATQN PIGKING MOTION FOR LOOMS 2 Sheets-Sheet 2 Filed Nov. 26, 1945 Patented Nov. 23, 1948 PICKING MOTION FOR LOOMS John Heaton, Riddiesden, Keighiey, England, as-

signor to Eiectro-Pneumatic Looms Limited, Bradford, England, a British company Application November 26, 1945, Serial No. 630,892 In Great Britain January 10, 1945 6 Claims. (01. 139-144) This invention relates to the picking motion of looms whether of the single or multi-shuttle box type.

The accepted form of picking motion now in use includes the use of mechanism wherein picking arms or sticks are tied by straps to pickers which are caused to strike the shuttle and thus drive it across the loom on the sley; This arrangement although universal has several disadvantages, such as, the constant breakage of picking arms, picking spindles and associated parts, the fact that a shuttle is liable to leave the sley with the possibility of attendant damage to the warp and/or 100m and risk of injury to the weaver. Also the constant blows on the shuttle,

in many cases, causes the latter to collapse or fracture so that in its passage along the sley it can whip splinters across the warp threads and thus cause considerable damage. Moreover, sudden blows in this manner do not tend to produce a smooth even velocity for the shuttles and the speed obtained is not all that is desired. The construction generally creates considerable noise and vibration with high stresses and strains in the various parts.

The object, of this invention is to provide an improved method of and means for applying motion to a loom shuttle.

Accordingly a method of impartingvmotion to a shuttle consists in the provision of air pressure as the driving force. Moreover, air pressure may be first built up and then released behind the shuttle.

According to a feature of the invention air pressure is directed on to the shuttle rear portion in the shuttle box whilst the shuttle bears against a seating through which the air passes. Also back air pressure created by a shuttle entering a shuttle box may be relieved automatically by valve means. The air inlet to a box may be in alignment with the shuttle or at an angle to its direction of travel. Air compression may be created by one or more pistons (or their equivalent) or obtained from a constant pressure supply source, and the compressed air controlled automatically by valve means to drive the shuttle in each direction across a loom. The said valve means may be displaceable by back air pressure when a shuttle enters a box to admit air back into the compression system.

Referring now to the accompanying drawings in which embodiments of the invention are shown by way of example only:

Fig. 1 is a general front elevation of the "going part of a loom fitted with single shuttle boxes and air pressure means;

Fig. 2 is a part front elevation of one end of the going part with double shuttle boxes;

Fig. 3 is a side elevation of the valve timing means; 7

Fig. 4 is a front elevation of a drop box construction incorporating six shuttle boxes;

Fig. 5 is an end view of a rotary box construction;

Fig. 6 is a plan view of a modified shuttle box construction;

Fig. '7 is a sectional plan view of a a single box with a modified air inlet.

One embodiment of the invention will now be described in simple form for a single shuttle type of loom (plain looms), i. e., a single shuttle box i at each end of the sley board I and secured to the bracket 3 at the upper end of the sword 4. As shown, the reed i is supported by the brackets 3 inm'iediately behind the sley board and the going part is operated by the usual forwardly extending arms connected to the swords and mounted on the crank shaft 6 supported by the loom frame I and driven in known manner. The general construction and operation of the "going part" can be according to known arrangements and does not form part of this invention which concerns the shuttle boxes and shuttle driving orce.

Each shuttle box I is of square tubular formation open at its inner exit end (the front and rear walls and top may be flared out slightly to facilitate the entry of a shuttle) and closed at its outer end. A union 8 is secured in the centre of the outer wall to provide an air inlet and an air pipe 9 links the union to the chamber ll of a control valve Ii which is operated by a solenoid l2 and returned by a spring it against an adjustable stop lla as more particularly shown in Figs. 2 and 5. The valve is adjusted to Just close the valve opening. The valve chambers are connected by pipes It to compression cylinders II secured to the swords and connected together by a compensator pipe it. A piston l1 (say of the leather washer type) is mounted ineach cylinder with its rod l8 anchored to a lever ll secured on a cross shaft 20 which is oscillated by a lever 2| through connecting .rod 22 and strap 23 mounted on an eccentric 14 secured on the crank shaft 6. The solenoids II are wired through connections 25, 28 to a timing device comprising contacts 21, I! which are engaged alternately by a movable selector switch 29 which in turn is wired by connection 30 to a movable contact 3| adapted to engage a contact 32 which is wired by connection 33 to the mains through a transformer, or to some other power source. As only a low power is required, say, 24 volts, 5 amps, the circuit is completed by grounding through the loom frame. The timing device is more particularly shown in Fig. 3 wherein the selector switch 29, between the contacts 21, 28, is connected by a rod 34 to a bellcrank lever 35 mounted on a spindle 36 and rocked by a. cam 31 secured on a higher spindle 33. A second cam 39 on spindle 36 moves the contact 3| into engagement with contact 32 and the gap may be adjusted by device 40. The spindles are geared together by gear wheels ll, 42 with a two to one reduction so that the contacts 3|, 32 close for every movement of the switch 23 which has alternate engagements. The spindle 33 is driven through chain wheel 43 and chain 44 from the crank shaft 6.

The operation is as follows: as the crank shaft rotates it not only moves the going part but operates the pistons H to compress air in cylinders l5, pipes l4 and I6 and valve chambers I0. When the pistons are almost at the top of their stroke one of the valves ll (saythe left hand valve in Fig. 1) is withdrawn by its solenoid l2 by the contacts 3|, 32 being closed and the selector switch 29 engaging the contact 21. Thus compressed air is admitted to the left hand shuttle box I behind the shuttle as the pistons are completing their stroke to ensure the shuttle receives the necessary impetus to fly quickly across the sley board into the opposite shuttle box. The going part continues its motion, forwardly then rearwardly again when the right hand valve is opened through contact 28 for compressed air to blow the shuttle back across the sley board and these operations continue with the shuttle being blown first from one box and then the other. The speed of the shuttle is such that it can fly across the sley board when the cranks are back centre and the shed" is thus open to its fullest extent as distinct from the known picking arm motion which, due to lack of speed, throws the shuttle through the shed before it is fully opened, thus having to force the warp threads apart. Furthermore, the air driven shuttle has a true flight so that it only brushes lightly against the reed with the minimum the old method the shuttle bears hard against the reed so that not only is its flight impeded but the reed Wires are worn away rapidly. .As the shuttle enters a shuttle box it forces air back through the pipe 9 and as the valve II is adjustable in stroke for controlling the air pressure by being spring loaded against an adjustable stop I3a, it is displaced sufficiently to enable the back pressure to be relieved and air to pass back into the compression system. Alternatively, back pressure could be relieved by an exhaust valve at the rear'of a box I, or in pipe 9, in which case the cylinders would have air inlets in known manner. A leather or other check washer 45 is provided at the rear of each box to act as a cushion for the shuttle although the speed of the shuttle is absorbed by the air in the shuttle box as the shuttle compresses it so that an air cushioning eifect is created. With the above arrangement air is injected through the washer which forms an air tight seating momentarily for the shuttle to ensure maximum force being obtained from the air pressure.

As shown in Fig. 2, each valve chamber III includes a cylindrical stop 13b adjustable axially of frictional resistance, whereas in slight movement against resilient pressure.

within the opening through solenoid l2 by means of a set screw I30 to adjust the lower abutment of spring I 3 and thereby adjust the back air cushion pressure on the shuttle at which the valve I I will open to permit air to be forced back through the valve into the air compression system as the piston I! in compressor I5 is rising. In operation, set screw He is set to such position that the momentum of the returning shuttle is entirely absorbed by the air cushion in the shuttle box, preferably the adjustment being made such that the shuttle when filled with the weftis brought to a stop just short of actual contact with the wall of the check Washer 45 thereby insuring maximum pneumatic shuttle propulsion force when the shuttle is full. The washer 45 also acts as a cushion to prevent damage to the shuttle in the event that the air valve is maladjusted or a fault develops. Since the return movement of the shuttle into the shuttle box is arrested entirely by the back pressure built up by the shuttle upon entering the shuttle box, any tendency on the part of the shuttle to rebound is eliminated. This is highly important since any rebound of the shuttle will cause the trailing weft to slacken and be of less tension than the other threads, and the finished cloth will show a mark at the place where the tension was lessened.

Use of an air cushion built up by compression oi. air by the returning shuttle upon entering the shuttle box has the further advantage that as the weft decreases and effects a corresponding decrease in the mass of the shuttle, the shuttle velocity will nevertheless remain constant because of the fact that whilst the pressure at the outlet of compressor l5 remains substantially constant, the shuttle penetrates the shuttle box a less distance as its mass decreases and thus the effective air pressure is not as great.

Whilst the air compressing and control means remain the same, the shuttle box construction may be modified to suit different types of looms.

For example, some looms are box type and then the boxes of the multi-shuttle are one unit or connected together and mounted in guides for drop boxes or on an axis for the rotary type. In Fig. 2, two boxes I are mounted in guides 46 and operated by the usual mechanism to register with the union 8 and sley board. Fig. 4 shows six boxes I mounted in guides 46' to be operated in known manner to register with the union 8 and sley board. Fig. 5 shows six boxes I rotatable about an axis 41 on carrier means 43 in known manner for a selected box to register with the sley board and the union 8 which admits air. In another embodiment of the invention shown in Fig. 6, each shuttle box la at each end of the sley mounted in guides 46a is constructed to have a fixed back plate, top and bottom and outer end with an open inner end and a movable front plate 49,. The movable front plate is normally held by a retaining spring 50 so that a shuttle in the box is held more or less lightly but firmly in position whilst the front plate is capable of In this manner, a shuttle is held firmly until it leaves the box but prior to the application of a driving force the grip is slightly resilient. This arrangement aids the shuttle to start with a true flight. The inner face of the movable plate may be covered with material 5| which serves to seal the joints and grip the shuttle but could be dispensed with. The plate is movable about a hinge 52 at the outer end of the box.

For some types of looms the driving force for the shuttle of compressed air may be admitted through an inlet 9' (or inlets) in the back plate as shown in Fig. 7, to strike the rear side face thrust towards the front box plate which can be fixed as shown, or adapted to give slightly as the shuttle is driven out of the box, whereby the nose of the shuttle tends to be thrust towards the inner wall (i. e., the reed 5) of the sley to counteract any tendency to fiy outwardly and a true flight is obtained.

The compressed air maybe provided from any other convenient source, such as a constant pressure supply source (a back pressure exhaust valve would then be required), instead of being supplied from compression means on the going part" of the loom or otherwise modified. For example, one compression cylinder could be used but with two, one balances the other and ensures compressed air ior either side. The air inlet 6 may be controllable by valve means to adjust the air pressure or speed of entry. Also, the air admission valves ll could be operated mechanically instead of electrically.

with this method, air bearing a certain amount of moisture can be blown around the warp to have a beneficial effect thereon and the tapered shuttle end divides the following air to spread it. The above constructions may be modified in a variety of ways without departing from the scope of the invention which affords a truer and faster 'fiight for a shuttle in all types of looms and removes all the aforesaid disadvantages of the picking motion. v

What I claim is:

1. Picking apparatus ior back and forth across a sley board comprising, a tubular shuttle box at each side of the sley board adapted to snugly receive theshuttle, a source of compressed air, means including alternately actuated valves for deliverin compressed air alternately to the shuttle boxes to directly propel the shuttle back and forth, and back air pressure relieving shuttle box, each such means being to thereby vary the arresting effect 0! the air cushion built up in each shuttle box by back air pressure upon a return oi the .shuttle to the box. 2. Picking apparatus for driving a loom shuttle across a sley board comprising. a tubular shuttle box at each side of the sley board adapted to snugly receive the shuttle, a source of compressed air, a pipe between each shuttle box and air source to deliver compressed air to the rear at said shuttle boxes for direct propulsion of the shuttle back and iorth across the sley board, a valve in each said pipe loaded to closed position, said valves being alternately opened .to admit compressed air alternately to the shuttleboxes and alternately opened under back air pressure established upon" a return oi the shuttle to. the shuttle box, and means for adjusting the loading on each 0! said valves to thereby provide regulation oi the air cushion in the shuttle box by means associated with eachdriving a loom shuttle adjustable by the loom 6 which motion of the returning shuttle is arrested. 3. Picking apparatus asdefined in claim 2 wherein each of said valves and the valve solenoids are from a source of current contactor device driven by 4. Picking apparatus as the loom.

defined in claim 2 wherein each of said valves is comprised of a.

spring loaded solenoid plunger, the valve solenoids are alternately driven by the loom, and further including means for adjusting the position or the valve plunger relative to the valve ports.

5. Pickingapparatus for driving a loom shuttle across a sley board comprising, a tubular shuttle box at each side of the sley board adapted .to snugly receive the shuttle, an air compressor associated with each shuttle box, pipe means between. the outlet of each compressor and its associatedshuttle box, each pipe, each of said valves being ,loaded to a normally closed position and openable either upon energization of the solenoid or upon a rise in back pressure, in the shuttle box and pipe upon return of the shuttle, a contactor device driven tor alternately connecting the valve solenoids to a source or current to deliver compressed air to first one shuttle other to propel the shuttle back and forth across the sley board, means for adjusting the contact setting of said contactor device to adjust the timing of said valves, and means for adjusting the loading or each valve adjustable air cushion for arresting motion of the shuttle upon enterlngeach shuttle box.

6. Picking apparatus as defined in claim 5 'whereln each air compressor is of the pistoncylinder type, and said valves are timed to open slightly in advance of the end of the compression air to the shuttle boxes.,

JOHN HEATON.

REFERENCES crr'Eb The following references are 'of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 357,097 Potts -J.-- Feb. 1, 1887 445,395 Cranston Jan. 27, 1891 659,951 Baker -r Oct. 16, 1900 891,728 Miniszewski Jan. 21, 1902 717,965 Blundell Jan. '8, 1903 1,007,733 Rhodes Nov. 7, 1911 1,308,190 Pickstone June 10, 1919 1,887,306 Brooks Apr. 24, 1928 2,377,800 Mascarenhas June 5., 1945 FOREIGN PATENTS Number Country Date 2,133 Great Britain 1884 3,499 Great Britain 1866 14,768 Great Britain 1911 is solenoid actuated alternately energized through an adjustable energized from a source of current through an adjustable contactor device a solenoid actuated valve in box and then the to thereby provide an 

